Why Good Nutrition Doesn’t Come from a Bottle

 

The U.S. Preventive Services Task Force just released a consensus statement urging Americans NOT to take antioxidant supplements of vitamin E and beta-carotene to attempt to reduce the risk of heart disease and cancer.

Studies consistently suggest that a healthy diet of vegetables, fruits, whole grains, lean proteins, and unsaturated fats is associated with lower rates of chronic disease.  However, the expert panel concluded that clinical trials of these antioxidant supplements have NOT produced the same benefit.  They may actually increase the risk for chronic disease in certain individuals.  For example, high doses of beta carotene supplementation have been associated with increased rates of lung cancer in smokers.

 

What about multivitamins?

Multivitamins or individual vitamin and mineral supplements may be helpful for certain populations such as pregnant women, individuals with severe dietary restrictions, and individuals with diagnosed nutrient deficiencies.

However, the panel states that it is unclear if healthy individuals will experience any reduction in chronic disease risk by taking daily multivitamins.

Be sure to consult with your health care professional before taking dietary supplements.

 

If some is good, more must be better… right?

Wrong.  A common misconception about vitamins and minerals is that higher doses provide greater benefit.  Some nutrients, such as iron and vitamin A, are extremely toxic when consumed in excess.  High doses of some nutrients may also hinder the absorption of others.  For example, iron, copper, zinc and calcium compete with one another for absorption.

 

Bottom Line

1.  Try to obtain most of your nutrients from whole foods:  vegetables, fruits, whole grain, beans, lean proteins, unsaturated fat.
2.  If you do not or cannot eat a balanced diet, a moderate level (less than 100% Daily Value) multi-vitamin/mineral supplement may be beneficial.  Consult with your health care provider.
3.  Independent analyses from Consumerlab.com usually indicate that the national brands (e.g., Centrum, One-a-day) and generic brands are acceptable and cost effective sources of moderate level multivitamins.
4.  Current research suggests that the spectrum of vitamins, minerals, phytochemicals, antioxidants, and fibers in foods has a greater impact on health than a few isolated nutrients in supplement form.  Supplements are no substitute for a healthy diet.

 

 References:

Physician’s Health Study II

“Among this population of US male physicians, taking a daily multivitamin did not reduce major cardiovascular events, MI, stroke, and CVD mortality after more than a decade of treatment and follow-up.”

Women’s Health Study

“In this population of apparently healthy women, vitamin E did not affect the overall risk of heart failure.”

Women’s Antioxidant Cardiovascular Study 

“Supplementation with vitamin C, vitamin E, or beta carotene offers no overall benefits in the primary prevention of total cancer incidence or cancer mortality.”

Alpha Tocopherol Beta Carotene (ATBC) Cancer Prevention

“Supplementation with alpha-tocopherol [vitamin E] or beta-carotene does not prevent lung cancer in older men who smoke. Beta-Carotene supplementation at pharmacologic levels may modestly increase lung cancer incidence in cigarette smokers, and this effect may be associated with heavier smoking and higher alcohol intake.”

Beta-Carotene and Retinol Efficacy Trial (CARET)

“CARET participants receiving the combination of beta-carotene and vitamin A had no chemopreventive benefit and had excess lung cancer incidence and mortality.”

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